Arsenal's Jack Wilshere's most noticeable impression on his side's game against Manchester United at the weekend was when he squared up to Marouane Fellaini.
Wilshere was clearly irked by the powerful Belgian and was lucky to stay on the pitch after appearing to headbutt the United star.
It was a show of frustration, but the action highlighted a worrying trait in Wilshere's game.
There can be no doubting the England international's technical ability, but his indiscipline is in danger of threatening his career.
Wilshere's immaturity on the football pitch is obvious and his tendency to pick fights with opposition players is something he needs to cut out of his game.
The 22-year-old is obviously still developing as a player, and having a certain amount of aggression is not a bad trait, but it needs to be channelled.
At the moment Wilshere looks more like a petulant child than a midfield enforcer and unless he shows more focus on driving his side forwards rather than scraping with opposition players it may limit his effectiveness on the pitch.
The Arsenal academy-product has started to show signs of huge improvements on the pitch, but this side of his game is something he will need to eradicate if he is to fulfil his potential.